The aim of passive detection and location systems is to detect the radiation of transmitters, locate them, and to determine their technical characteristics so as to facilitate their identification. Their basic principle is to determine the positioning of the transmitters by using the information provided by their transmission.
Passive detection and location techniques generally implement the principle of triangulation between sighting lines using several goniometric measurements of radiations transmitted by the radar transmitters to be located.
This triangulation scheme is a technique which gives good results on condition on the one hand that there is no ambiguity in the identification of the common point sighted, on the other hand that the geometric disposition of the listening system is sufficiently open. The problem of ambiguous association occurs when several transmitters are present in the surveillance field of the passive sensors or ESMs (Electronic Support Measures). Indeed, passive sensors, unable to measure the distance separating them from the transmitter, can only provide an angle of arrival of the intercepted wave. In this context, there then exist intersections of sighting lines not corresponding to real transmitters but to phantom or ghost sources. This phenomenon is illustrated in FIG. 1b. It is then a matter of dealing with a problem in decision theory, that is to say of devising a test making it possible to adjudicate between two complementary hypotheses, namely, do the tracks of the sensors originate from the same source or not. If only the geometric information is considered, the problem of association is then formulated based on the angle of the association of the ESM angular plots. The absence of the distance parameter makes it an “ill-posed” problem.
This problem of association of angular plots can be solved by optimization algorithms of significant computational complexity. This complexity quickly becomes crippling in dense environments of radar transmissions.
An aim of the invention is notably to correct the aforementioned drawbacks by proposing a solution making it possible to rapidly eliminate phantom or ghost sources and to associate radar tracks originating from one and the same source.